Large increases in methane emissions expected from North America's largest wetland complex

Area of Science:

• Environmental Science
• Climate Science
• Ecology

Background:

• Human-induced climate warming may increase natural methane (CH4) emissions from aquatic ecosystems.
• The precise magnitude of this increase remains uncertain.

Purpose of the Study:

• To model plot- and landscape-scale wetland CH4 emissions from the Prairie Pothole Region (PPR).
• To assess the impact of climate warming on future CH4 emissions in this major North American wetland complex.

Main Methods:

• Utilized a large dataset of CH4 flux measurements (~19,000 chamber measurements).
• Integrated remotely sensed information to model CH4 emissions.
• Analyzed factors influencing plot-scale emissions (hydrology, temperature, vegetation, wetland size).

Main Results:

• Plot-scale CH4 emissions were significantly influenced by hydrological conditions, temperature, vegetation, and wetland size.
• Historically, landscape-scale emissions in the PPR were primarily linked to overall wetland extent.
• Despite potential changes in wetland extent, PPR CH4 emissions are projected to increase two- to threefold by 2100 under moderate to severe warming scenarios.

Conclusions:

• Future climate warming is predicted to substantially increase natural methane emissions from the Prairie Pothole Region.
• International climate mitigation efforts must incorporate both anthropogenic and natural CH4 sources to meet long-term targets.
• Accounting for these natural emissions is crucial for accurate climate projections and effective policy development.